 In 1904, Friedeberg, speaking for the FVdG, advanced the view that the general strike must be a weapon in the hands of the proletariat and would be the last step before the socialist revolution.In 1905, his speech on the topic was even more radical.He claimed that historical materialism, a pillar of Marxism, was to blame for social democracy's alleged powerlessness, and introduced the alternative concept of "historical psychism"—which held that human psychology was more significant for social development than material conditions.